we cannot afford four more years of barack obama. we're not going to have four more years of barack obama. >> the road to the white house runs through ohio, that's why the candidates have made more than 30 visits here already. the fact is that in this huge country, the election will be decided in just a few places like this. this is the most expensive presidential race ever. the two parties have already spent more than $1 billion in all, much of it focused on just eight of america's 50 states. over a third of then ca otilil on political adverts swaying undecided voters, roughly a million people, around 3% of those who plan to vote. >> maybe instead of attacking others on taxes, romney should come clean on his. >> trying to reach these vital voters, the two campaigns have spent $116 million on tv ads in ohio alone, most attacking their opponent. >> fewer americans are working today than when president obama took office. >> but if the air war is important, the ground war could be important. an emotional opening of the latest obama camp